<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var socket;
    //判断当前浏览器是否支持WebSocket
    if (window.WebSocket) {
        //go on
        socket = new WebSocket("ws://localhost:9999/hello");
        //相当于channelRead ev 收到服务器端回送的消息
        socket.onmessage = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = rt.value + "\n" + ev.data;
        }
        //相当于连接开始
        socket.onopen = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = "连接开启...";
        }
        //相当于连接关闭（感知连接关闭）
        socket.onclose = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = rt.value + "\n" + "链接关闭了...";

        }
    } else {
        alert("当前浏览器不支持WebSocket编程")
    }
    //发送消息服务器
    function send(message) {
        if (!window.socket) { //判断socket是否建立好
            return;
        }
        if (socket.readyState == WebSocket.OPEN) {
            //通过socket发送消息
            socket.send(message);
        } else {
            alert("链接没有开启");
        }

    }

</script>
<form onsubmit="return false">
    <textarea name="message" style="height: 300px;width: 300px"></textarea>
    <input type="button" value="发送消息" onclick="send(this.form.message.value)">

    <textarea id="responseText" style="height: 300px;width: 300px"></textarea>
    <input type="button" value="清空内容" onclick="document.getElementById('responseText').value=''">
</form>
</body>
</html>